Fluid distribution network for large stator motor

ABSTRACT

A reaction assembly ( 20 ) for supporting a mover ( 18 ) includes a countermass assembly ( 26 ) and a fluid distribution network ( 28 ). The fluid distribution network ( 28 ) allows for circulating a fluid ( 30 ) to provide cooling for the portion of the mover ( 18 ). The fluid distribution network ( 28 ) is positioned substantially adjacent to the countermass assembly ( 26 ), and the fluid distribution network ( 28 ) being substantially thermally decoupled from the structure of the countermass assembly ( 26 ) to inhibit thermal deformation of the countermass assembly ( 26 ).

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority on U.S. Provisional Application Ser. No. 61/878,517 filed on Sep. 16, 2013 and entitled “FLUID DISTRIBUTION NETWORK FOR LARGE STATOR MOTOR”. As far as is permitted, the contents of U.S. Provisional Application Ser. No. 61/878,517 are incorporated herein by reference.

BACKGROUND

Exposure apparatuses are commonly used to transfer images from a reticle onto a semiconductor wafer during semiconductor processing. A typical exposure apparatus includes an illumination source, a reticle stage assembly that retains a reticle, a lens assembly and a wafer stage assembly that retains a semiconductor wafer. Typically, the wafer stage assembly includes a wafer stage base, a wafer stage that retains the wafer, and a wafer stage mover assembly that precisely positions the wafer stage and the wafer. Somewhat similarly, the reticle stage assembly includes a reticle stage base, a reticle stage that retains the reticle, and a reticle stage mover assembly that precisely positions the reticle stage and the reticle. The size of the images and the features within the images transferred onto the wafer from the reticle are extremely small. Accordingly, the precise relative positioning of the wafer and the reticle is critical to the manufacturing of high density, semiconductor wafers.

Unfortunately, the stage mover assemblies generate heat that can influence the other components of the exposure apparatus. Conventionally, the stage mover assemblies are cooled by forcing a coolant around the movers of the stage mover assembly. However, existing coolant systems do not adequately or efficiently cool the movers of the stage mover assembly. Additionally, existing coolant systems do not adequately or efficiently inhibit pressure loss, i.e. pressure drops, or thermal deformation within the stage mover assembly. This can reduce the accuracy of positioning of the wafer relative to the reticle, and degrade the accuracy of the exposure apparatus.

SUMMARY

The present invention is directed to a reaction assembly for supporting a mover relative to a base. In certain embodiments, the reaction assembly comprises a countermass assembly and a fluid distribution network. The countermass supports a portion of the mover. Additionally, the fluid distribution network allows for circulating a fluid to provide cooling for the portion of the mover. The fluid distribution network is positioned substantially adjacent to the countermass assembly, the fluid distribution network is substantially decoupled from the structure of the countermass assembly to inhibit thermal deformation of the countermass. Further, the fluid distribution network can be designed to inhibit pressure drops within the fluid distribution network.

In some embodiments, the countermass assembly includes a distribution plate assembly. In such embodiments, a majority of the fluid distribution network is positioned below and substantially adjacent to a bottom surface of the distribution plate assembly. Additionally, the distribution plate assembly can include a plurality of unit apertures, each unit aperture being adapted to receive one of a plurality of coil units. In one embodiment, the fluid distribution network is adapted to supply circulation fluid to the coil units to cool the coil units. Moreover, in one embodiment, the fluid distribution network includes a Coil Temperature Control network for cooling individual coils within the coil units, and a Surface Temperature Control network for cooling a surface of the coil units.

The present invention is further directed toward a stage assembly including a stage base, a stage that retains a device, a stage mover that moves the stage relative to the stage base, and the reaction assembly as described above that supports a portion of the stage mover. In one embodiment, the stage mover includes a conductor array having a plurality of coil units, and the fluid distribution network provides cooling for the coil units. Additionally, the present invention is further directed toward an exposure apparatus including the stage assembly as described above that retains the device, and an illumination source that guides a beam of light energy toward the device; and a process for manufacturing a wafer that includes the steps of providing a substrate, and transferring a mask pattern to the substrate with the exposure apparatus.

In another application, the present invention is also directed toward a reaction assembly for supporting a mover relative to a base, the reaction assembly comprising (i) a countermass assembly that supports a portion of the mover, the countermass assembly including a distribution plate assembly; and (ii) a fluid distribution network that cools the portion of the mover, a majority of the fluid distribution network being positioned below and substantially adjacent to a bottom surface of the distribution plate assembly.

In still another application, the present invention is further directed toward a reaction assembly for supporting a mover relative to a base, the reaction assembly comprising (i) a distribution plate assembly that supports a portion of the mover including a plurality of passageways; and (ii) a fluid distribution network including a fluid source that provides a circulation fluid that cools the portion of the mover, wherein the passageways extend between the fluid distribution network and the portion of the mover, the passageways providing the only source of the circulation fluid within the distribution plate assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:

FIG. 1 is a perspective view of an embodiment of a stage assembly having features of the present invention;

FIG. 2A is a simplified view of a coil unit, a portion of a distribution plate assembly, and a portion of a fluid distribution network having features of the present invention;

FIG. 2B is a perspective view of the coil unit of FIG. 2A;

FIG. 3A is a top plan view of the distribution plate assembly of FIG. 2A;

FIG. 3B is a top plan view of a portion of the distribution plate assembly of FIG. 3A;

FIG. 3C is a bottom plan view of the portion of the distribution plate assembly of FIG. 3B;

FIG. 3D is a cut-away view taken on line 3D-3D in FIG. 3C;

FIG. 4A is a simplified bottom view of the distribution plate assembly and a portion of the fluid distribution network;

FIG. 4B is a bottom view of the portion of the fluid distribution network of FIG. 4A;

FIG. 4C is a top view of the portion of the fluid distribution network of FIG. 4A;

FIG. 4D is a cutaway perspective view taken from FIG. 4C;

FIG. 5A is a bottom perspective view of a portion of the fluid distribution network;

FIG. 5B is a bottom view of the portion of the fluid distribution network of FIG. 5A;

FIG. 6A is a bottom perspective view of a distribution conduit array;

FIG. 6B is a top view of the portion of the distribution conduit array of FIG. 6A;

FIG. 6C is an inverted side view of the distribution conduit array;

FIG. 7A is a bottom perspective view of a portion of the fluid distribution network;

FIG. 7B is a bottom view of the portion of the fluid distribution network of FIG. 7A;

FIG. 8A is a perspective view of a connector that can be used to connect a portion of the fluid distribution network to the distribution plate;

FIG. 8B is a perspective view of a portion of the distribution plate and the connector of FIG. 8A;

FIG. 9 is a schematic illustration of an exposure apparatus having features of the present invention;

FIG. 10A is a flow chart that outlines a process for manufacturing a device in accordance with the present invention; and

FIG. 10B is a flow chart that outlines device processing in more detail.

DESCRIPTION

FIG. 1 is a perspective view of an embodiment of a stage assembly 10 having features of the present invention. As illustrated in this embodiment, the stage assembly 10 includes a stage base 12, a stage 14 that retains a device 16, a stage mover 18, a countermass reaction assembly 20 (also referred to herein simply as a “reaction assembly”), and a control system 22. The design of each of these components can be varied to suit the design requirements of the stage assembly 10. In certain applications, the stage assembly 10 can be positioned above a mounting base 24 (illustrated in FIG. 9). The stage mover 18 precisely moves the stage 14 and the device 16 relative to the stage base 12 and the reaction assembly 20.

As an overview, in certain embodiments, the reaction assembly 20 includes (i) a countermass assembly 26 that supports a portion of the stage mover 18, and (ii) a fluid distribution network 28 that effectively and efficiently controls the flow of fluid in and around the stage mover 18 and the reaction assembly 20. More particularly, the fluid distribution network 28 is designed to inhibit undesired pressure drops while distributing a large volume of fluid over a relatively large area of the stage assembly 10. Additionally, the fluid distribution network 28 is designed to be substantially decoupled from the physical structure of the countermass assembly 26 to more effectively manage the thermal strain that may otherwise exist within the stage assembly 10, e.g., within the stage mover 18.

Further, the fluid distribution network 28 directs a circulation fluid 30 (illustrated with small circles) to a portion of the stage mover 18 and the countermass assembly 26 to control the temperature around the stage mover 18 and reaction assembly 20. In one embodiment, the fluid distribution network 28 includes (i) a body fluid source 32 that circulates the circulation fluid 30 to primarily remove the heat from the stage mover 18 and the countermass assembly 26; and (ii) a surface fluid source 32 that circulates the circulation fluid 30 to control the temperature of the upper surface of a portion of the stage mover 18 to inhibit the transfer of heat from the stage mover 18 to the surrounding environment. It should be noted that either of the fluid sources 32, 34 can be referred to as a first fluid source or a second fluid source.

In FIG. 1, each fluid source 32, 34 is illustrated as including a single source outlet 35A, and a single source inlet 35B. Alternatively, each fluid source 32, 34 can include multiple source outlets and source inlets. Further, the fluid sources 32, 34 can be combined into a single system or more than two systems. Moreover, each fluid source 32, 34 can include one or more pumps, reservoirs, flow regulators, pressure regulators, valves, temperature controllers, chillers, and/or heaters to precisely control the temperature and flow rate of the fluid 30.

In certain embodiments, the body fluid source 32 independently controls the flow rate of the circulation fluid 30 to different areas of the stage mover 18 so that more circulation fluid 30 can be directed to the areas of the stage mover 18 that are used the most and that are generating the most heat, and less is directed to the areas that are used the least and that are generating less heat. Moreover, in certain embodiments, the circulation fluid 30 can be provided at a high flow rate to a large area of the stage mover 18 while inhibiting thermal deformation and providing a manufacturable design by using a modular design to create a fluid flow network wherein the circulation fluid 30 flows primarily in non-structural parts, and wherein the fluid distribution network 28 is configured in a hierarchical (tree) manner. This will allow for the efficient cooling of the stage mover 18. Still further, the fluid distribution network 28 can efficiently and accurately maintain a substantially uniform temperature of the stage mover 18 and the reaction assembly 20, which, in turn, allows for more accurate positioning of the stage 14 and the device 16.

The stage assembly 10 is particularly useful for precisely positioning the device 16 during a manufacturing and/or an inspection process. The type of device 16 positioned and moved by the stage assembly 10 can be varied. For example, the device 16 can be a semiconductor wafer, and the stage assembly 10 can be used as part of an exposure apparatus for precisely positioning the semiconductor wafer during manufacturing of the semiconductor wafer. Alternatively, for example, the stage assembly 10 can be used to move other types of devices during manufacturing and/or inspection, to move a device under an electron microscope (not shown), or to move a device during a precision measurement operation (not shown).

Some of the Figures provided herein include an orientation system that designates an X axis, a Y axis, and a Z axis. It should be understood that the orientation system is merely for reference and can be varied. For example, the X axis can be switched with the Y axis and/or the stage assembly 10 can be rotated. Moreover, these axes can alternatively be referred to as a first, second, or third axis.

The stage base 12 supports a portion of the stage assembly 10 above the mounting base 24. In the embodiment illustrated herein, the stage base 12 is rigid and generally rectangular shaped.

As noted above, the stage 14 retains the device 16. Further, the stage 14 is precisely moved by the stage mover 18 to precisely position the device 16. In the embodiments illustrated herein, the stage 14 is generally rectangular shaped and includes a device holder (not shown) for retaining the device 16. The device holder can be a vacuum chuck, an electrostatic chuck, or some other type of clamp.

The stage 14 can be maintained spaced apart from (e.g., above) the reaction assembly 20 with the stage mover 18 if the stage mover 18 is a six degree of freedom mover that moves the stage 14 relative to the reaction assembly 20 with six degrees of freedom. In this embodiment, the stage mover 18 functions as a magnetic type bearing that levitates the stage 14. Alternatively, for example, the stage 14 can be supported relative to the reaction assembly 20 with a stage bearing (not shown), e.g., a vacuum preload type fluid bearing. For example, the bottom of the stage 14 can include a plurality of spaced apart fluid outlets (not shown), and a plurality of spaced apart fluid inlets (not shown). In this example, pressurized fluid (not shown) can be released from the fluid outlets towards the reaction assembly 20 and a vacuum can be pulled in the fluid inlets to create a vacuum preload type, fluid bearing between the stage 14 and the reaction assembly 20. In this embodiment, the stage bearing allows for motion of the stage 14 relative to the reaction assembly 20 along the X axis, along the Y axis and about the Z axis.

The stage mover 18 controls and adjusts the position of the stage 14 and the device 16 relative to the reaction assembly 20 and the stage base 12. For example, the stage mover 18 can be a planar motor that moves and positions the stage 14 along the X axis, along the Y axis and about the Z axis (“three degrees of freedom” or “the planar degrees of freedom”). Further, in certain embodiments, the stage mover 18 can also be controlled to move the stage 14 along Z axis and about the X and Y axes. With this design, the stage mover 18 is a six degree of freedom mover. Alternatively, in certain embodiments, the stage mover 18 can be another type of actuator designed to move the stage 14 with less than six degrees of freedom.

In the embodiments illustrated herein, the stage mover 16 includes a conductor array 36, and an adjacent magnet array 38 that interacts with the conductor array 36. In FIG. 1, the conductor array 36 is coupled to the reaction assembly 20, and the magnet array 38 is secured to the stage 14. Alternatively, in one embodiment, the conductor array 36 can be coupled to the stage 14 and the magnet array 38 can be coupled to the reaction assembly 20. As provided herein, the array secured to the stage 14 can be referred to as the moving component of the stage mover 18, and the array secured to the reaction assembly 20 can be referred to as the reaction component (or stator) of the stage mover 18.

In one embodiment, the conductor array 36 can include a plurality of coil units 40, and each coil unit 40 can include a single coil (not shown) that is oriented to provide movement along the X-axis or the Y-axis. Alternatively, each coil unit 40 can include more than one coil (e.g. three coils). Still alternatively, each coil unit 40 can include one of more coils that is oriented to provide movement along the X-axis, and one or more coils that is oriented to provide movement along the Y-axis. Each coil can be made of a metal such as copper or any substance or material responsive to electrical current and capable of creating a magnetic field such as superconductors.

The design and number of coil units 40 in the conductor array 36 can vary according to the performance and movement requirements of the stage mover 18. For example, in the embodiment illustrated in FIG. 1, the conductor array 36 includes two hundred sixty-four coil units 40 that are arranged in a generally rectangular twelve by twenty-two array. Additionally, the individual coil units 40 can be arranged such that a plurality of Y-coil units and a plurality of X-coil units are positioned and/or arranged in an alternating pattern in both the X-direction and the Y-direction. Thus, in such embodiment, the conductor array 36 includes one hundred thirty-two X-coil units 40 and one hundred thirty-two Y-coil units 40 that are arranged in an alternating pattern in both the X-direction and the Y-direction.

Further, the magnet array 38 can include one or more magnets (not illustrated) that interact with the plurality of coil units 40. The design of the magnet array 38 and the number of magnets in the magnet array 38 can be varied to suit the design requirements of the stage mover 18. In some embodiments, each magnet can be made of a permanent magnetic material such as NdFeB.

Electrical current (not shown) is supplied to the coil units 40 by the control system 22. The electrical current in the coil units 40 interacts with the magnetic field(s) of the one or more magnets in the magnet array 38. This causes a force (Lorentz type force) between the coil units 40 and the magnets that can be used to move the stage 14 relative to the stage base 12.

Unfortunately, the electrical current supplied to the coil units 40 also generates heat, due to resistance in the coil units 40. The heat from the coil units 40 is subsequently transferred to the reaction assembly 20. This can cause expansion and distortion of the reaction assembly 20. Further, the heat from the coil units 40 can be transferred to the surrounding environment, including the air surrounding the coil units 40. This can adversely influence a measurement system (not shown in FIG. 1) that measures the position of the stage 14 and the device 16. For example, certain measurement systems utilize one or more interferometers. The heat from the conductor array 36 changes the index of refraction of the surrounding air. This reduces the accuracy of the measurement system and degrades machine positioning accuracy. Moreover, the resistance of the coil units 40 increases as temperature increases. This exacerbates the heating problem and reduces the performance and life of the stage mover 16.

In certain embodiments, to reduce the influence of the heat from the coil units 40, the present invention actively cools the reaction assembly 20 and the coil units 40 using the fluid distribution network 28.

The reaction assembly 20 counteracts, reduces and/or minimizes the influence of the reaction forces from the stage mover 18 on the position of the stage base 12 relative to the mounting base 1324. This minimizes the distortion of the stage base 12 and improves the positioning performance of the stage assembly 10. Further, for an exposure apparatus 1334, this allows for more accurate positioning of the semiconductor wafer.

As provided above, in the embodiment illustrated in FIG. 1, the conductor array 36 of the stage mover 18 is coupled to the reaction assembly 20. With this design, the reaction forces generated by the stage mover 18 are transferred to the reaction assembly 20. As a result thereof, when the stage mover 18 applies a force to move the stage 14, an equal and opposite reaction force is applied to the reaction assembly 20.

In FIG. 1, the reaction assembly 20 includes the generally rectangular shaped countermass assembly 26, which can be maintained above the stage base 12 with a reaction bearing (not shown), e.g. a vacuum preload type fluid bearing. For example, the bottom of the countermass 26 of the reaction assembly 20 can include a plurality of spaced apart fluid outlets (not shown), and a plurality of spaced apart fluid inlets (not shown). Pressurized fluid (not shown) can be released from the fluid outlets towards the stage base 12 and a vacuum can be pulled in the fluid inlets to create a vacuum preload type, fluid bearing between the stage base 12 and the countermass 26. In this embodiment, the reaction bearing allows for motion of the reaction assembly 20 relative to the stage base 12 along the X axis, along the Y axis and about the Z axis. Alternatively, for example, the reaction bearing can be a magnetic type bearing that provides for relative motion along the X, Y, and Z axes and about the X, Y, and Z axes, or a roller bearing type assembly.

With this design, through the principle of conservation of momentum, (i) movement of the stage 14 with the stage mover 16 along the X axis in a first X direction along the X axis, generates an equal but opposite X reaction force that moves the reaction assembly 20 in a second X direction that is opposite the first X direction along the X axis; (ii) movement of the stage 14 with the stage mover 16 along the Y axis in a first Y direction, generates an equal but opposite Y reaction force that moves the reaction assembly 20 in a second Y direction that is opposite the first Y direction along the Y axis; and (iii) movement of the stage 14 with the stage mover 16 about the Z axis in a first theta Z direction, generates an equal but opposite theta Z reaction force (torque) that moves the reaction assembly 20 in a second theta Z direction that is opposite the first theta Z direction about the Z axis.

The design of the reaction assembly 20 can be varied to suit the design requirements of the stage assembly 10. In certain embodiments, the ratio of the mass of the reaction assembly 20 to the mass of the stage 14 is relatively high. This will minimize the movement of the reaction assembly 20 and minimize the required travel of the reaction assembly 20. A suitable ratio of the mass of the reaction assembly 20 to the mass of the stage 14 is between approximately 10:1 and 30:1. A larger mass ratio is better, but is limited by the physical size of the reaction assembly 20.

In one embodiment, the reaction assembly 20 is made from a non-electrically conductive, non-magnetic material, such as low electrical conductivity stainless steel or titanium, or non-electrically conductive plastic or ceramic.

Additionally, one or more movers (not shown) can be used to adjust the position of the reaction assembly 20 relative to the stage base 12 and/or to counteract moments imparted onto the reaction assembly 20. For example, the movers can include one or more rotary motors, voice coil motors, linear motors, electromagnetic actuators, or other type of actuators.

The fluid distribution network 28 reduces the influence of the heat from the coil units 40 of the conductor array 36 from adversely influencing the other components of the stage assembly 10 and the assemblies nearby the stage assembly 10. In one embodiment, the fluid distribution network 28 efficiently reduces the amount of heat transferred from the coil units 40 to the surrounding environment.

The design of the fluid distribution network 28 can vary. In certain embodiments, the fluid distribution network 28 uses a multi-layer design approach, with each layer being designed to minimize or inhibit pressure drops and the impact of thermal deformation on the countermass 26. As described herein, the fluid management provided via the fluid distribution network 28 and the structural support of the countermass 26 and the other supporting members of the stage assembly 10 are mostly decoupled from one another.

As described in greater detail herein below, in some embodiments, the fluid distribution network 28 can include and/or incorporate two distinct fluid networks. In particular, the fluid distribution network 28 can include the body fluid source 32 (sometimes referred to as the “first distribution network” or the “Coil Temperature Control (CTC) network”) that is used for cooling the coils within the coil units 40, which removes the bulk of the heat from the conductor array 36. Additionally, the fluid distribution network 28 can further include the surface fluid source 34 (sometimes referred to as the “second distribution network” or the “Surface Temperature Control (STC) network”) that is used for cooling and/or maintaining the temperature of the upper surface (typically the surface that faces the magnet array) of the individual coil units 40. The second distribution network 34 is used to shield the area above the coil units 40 from heat generated by the coil units 40. For mechanical considerations, because of the delicate nature of the coil units 40, the internal fluid pressure is limited. In order to achieve the often desired high flow rates to the large conductor array 36, limiting the pressure drop downstream to the coil units 40 is critical.

Further, the fluid distribution network 28 must be able to minimize and/or inhibit heat transfer to the countermass assembly 26. With the present design, the circulation fluid 30 can be provided at a high rate while minimizing and/or inhibiting thermal deformation by having the circulation fluid 30 flow primarily in non-structural parts. More specifically, with the large mass of the stage 14 and its high acceleration during certain applications, a significant amount of heat needs to be removed from the coils units 40 and the countermass assembly 26. Even with a high flow rate of the circulation fluid 30 there can be a substantial rise in fluid temperature. The difference between the hot and cold fluid, if not managed properly, can lead to thermal deformation of the countermass assembly 26, which in turn could impact the fly height of the stage 14, the accuracy of sensors, and the overall precision of the stage assembly 10. Moreover, with the design illustrated and described herein, the fluid distribution network 28 can be used to inhibit the transfer of heat from the coil units 40 of the conductor array 36 to the surrounding environment.

The type of circulation fluid 30 that is utilized within the fluid distribution network 28 can be varied. For example, in certain embodiments, the circulation fluid 30 can be water or another appropriate cooling fluid. Additionally, the circulation fluid 30 can also be referred to as a coolant.

As provided herein, during use of the stage assembly 10, the device 16 is moved by the stage mover 18. Typically, during use of the stage assembly 10, more current is directed to certain of the coil units 40 as compared to other coil units 40. For example, certain coil units 40 are primarily used to move the device 16, e.g., a wafer, during the scanning portion of an exposure. These coil units 40 will generate more heat and, thus, will require more cooling. As provided herein, the fluid distribution network 28 is uniquely designed to provide more cooling to certain coil units 40 and/or groups of coil units 40. The design of the fluid distribution network 28 is discussed in more detail below.

The control system 22 is electrically connected to, and directs and controls electrical current to the coil units 40 of the stage mover 18 to precisely position the device 16. Further, the control system 22 is electrically connected to and controls the fluid distribution network 28 to accurately control the temperature of the reaction assembly 20 and the conductor units 40. The control system 22 can include one or more processors and/or circuits.

The design of the countermass assembly 26 can be varied pursuant to the teachings provided herein to suit the specific design requirements of the stage assembly 10. In one embodiment, the countermass assembly 20 includes (i) a fluid distribution plate assembly 48, (ii) a support frame 50, (iii) a plate attachment assembly 51; and (iv) one or more countermasses 52.

The fluid distribution plate assembly 48 supports the coil units 40 and also functions as a manifold to direct the circulation fluid 30 between the fluid distribution network 28 and the coil units 40. Thus, in certain embodiments, the fluid distribution plate assembly 48 provides structural support for the coil units 40 and is used with the fluid distribution network 28 for thermal control of the coil units 40. With this design, (i) reaction forces from the coil units 40 are transferred to the distribution plate assembly 48, then the plate attachment assembly 51, and subsequently to the support frame 50 and the countermass weights 52; and (iii) the circulation fluid 30 travels between the coil units 40 and the fluid distribution network 28 through the distribution plate assembly 48.

In certain embodiments, the fluid distribution plate assembly 48 is designed to enable the fluid distribution network 28 to be effectively decoupled from the physical structure of the stage assembly 10 to more effectively manage the thermal strain that may otherwise exist within the countermass assembly 26. In certain embodiments, the fluid distribution plate assembly 48 is the only part of the countermass assembly 26 that is used with the fluid distribution network 28 for thermal control of the coil units 40. Stated in another fashion, the only part of the countermass assembly 26 in which the fluid 30 flows is the distribution plate assembly 48. Thus, in these embodiments, (i) the fluid distribution plate assembly 48 is the only part of the countermass assembly 26 that is subjected to potential thermal deformation caused by the circulation fluid 30; and (iii) the other components (e.g. the support frame 50, the plate attachment assembly 51, and the countermasses 52) of the countermass assembly 26 are not subjected to potential thermal deformation caused by the circulation fluid 30. This minimizes the potential for thermal stain of the countermass assembly 26 that can adversely influence the position of the stage 14.

Moreover, in certain embodiments, the mass of the fluid distribution plate assembly 48 is relatively small when compared to the other components (e.g. the support frame 50, the plate attachment assembly 51, and the countermasses 52) of the countermass assembly 26. In this embodiment, when the circulation fluid 30 only flows through the fluid distribution plate assembly 48 of the countermass assembly 26, the fluid distribution network 28 is substantially decoupled from the physical structure of the countermass assembly 26 to more effectively manage the thermal strain that may otherwise exist within the countermass assembly 26. In alternative, non-exclusive embodiments, the circulation fluid 30 only flows through five, ten, fifteen, or twenty percent of the mass of the countermass assembly 26.

In the embodiment illustrated in FIG. 1, the fluid distribution plate assembly 48 is generally rectangular plate shaped and rigid. In certain embodiments, the fluid distribution plate assembly 48 can be made as a modular unit that includes a plurality of substantially similar fluid distribution plates 48A. As a non-exclusive example, the fluid distribution plate assembly 48 can include eleven fluid distribution plates 48A that are secured together in a side-by-side manner so as to provide a supporting mechanism to support the plurality of coil units 40. In this embodiment, each fluid distribution plates 48A is generally rectangular plate shaped and supports twenty-four separate coil units 40 (two rows of twelve coil units 40). Additionally, in this embodiment, each distribution plate 48A extends from one side of the distribution plate assembly 48 to the other side of the distribution plate assembly 48 in the X-direction (i.e. the shorter dimension as illustrated in the Figures), and the distribution plates 248 are positioned side-by-side in the Y-direction (i.e. the longer dimension as illustrated in the Figures).

Alternatively, the fluid distribution plate 48A can have a different shape or design. Still alternatively, the distribution plate assembly 48 can be made as single plate.

The support frame 50 supports the other components of the countermass assembly 26. In FIG. 1, the support frame 50 is generally rectangular plate shaped and rigid. Further, the support frame 50 is positioned adjacent to the stage base 12. In certain embodiments, the circulation fluid 30 does not flow through (or contact) the support frame 50.

The plate attachment assembly 51 is rigid and supports and rigidly couples the fluid distribution plate assembly 48 to the support frame 50, while allowing space for the fluid distribution network 28 to access a bottom of the fluid distribution plate assembly 48. In certain embodiments, the circulation fluid 30 does not flow through (or contact) the plate attachment assembly 51.

The one or more countermass weights 52 are coupled to the distribution plate assembly 48 and/or the support frame 50 to provide a greater mass to the reaction assembly 20 so as to minimize or otherwise limit any movement of the reaction assembly 20 in reaction to the movement of the stage 14 (illustrated in FIG. 1) by the stage mover 18. For example, in one embodiment, the countermass weights 52 can comprise tungsten blocks that are coupled to an end of the distribution plate assembly 48 and/or the support frame 50. Alternatively, the countermass weights 52 can be made from another suitable material, and/or can be positioned in a different manner relative to the distribution plate assembly 48 and/or the support frame 50. In certain embodiments, the circulation fluid 30 does not flow through (or contact) the one or more countermass weights 52.

Additionally, as noted above, in certain embodiments, the countermass weights 52 can have sufficient mass such that the overall mass of the reaction assembly 20 versus the mass of the stage 14 can be between approximately 10:1 and 30:1. Alternatively, the mass of the reaction assembly 20 versus the mass of the stage 14 can be greater than 30:1 or less than 10:1.

FIG. 2A is a simplified, non-exclusive side view of one coil unit 40, a portion of the distribution plate assembly 48, and a portion of the fluid distribution network 28. The design of each of these components can be varied pursuant to the teachings provided herein.

In FIG. 2A, the coil unit 40 is generally rectangular shaped. In this non-exclusive embodiment, moving from the bottom to the top, the coil unit 40 includes (i) a lower body circulation plate 240A that is substantially rectangular plate shaped and includes one or more fluid passageways 240B, e.g. microchannels, (illustrated in phantom); (ii) a coil set 240C that includes one or more X coils and/or one or more Y coils; (iii) an upper body circulation plate 240D that is substantially rectangular plate shaped and includes one or more fluid passageways 240E (illustrated in phantom); and (iv) an upper surface circulation plate 240F that is substantially rectangular plate shaped and includes one or more fluid passageways 240G (illustrated in phantom). With this design, (i) the body fluid source 32 (illustrated in FIG. 1) directs the fluid 30 (illustrated in FIG. 1) through the body circulation plates 240A, 240D to remove the bulk of heat generated by the coil set 240C, and (ii) the surface fluid source 34 (illustrated in FIG. 1) directs the fluid 30 (illustrated in FIG. 1) through the surface circulation plate 240F to provide a thermal shield for the coil unit 40 and to maintain the surface temperature of each conductor unit 40 at the desired temperature to inhibit the transfer of heat from each conductor unit 40.

The design of the coil set 240C and the number of conductors in each coil set 240C can be varied to suit the design requirements of the stage mover 16 (illustrated in FIG. 1). For a three phase planar motor, each coil set 240C includes three adjacent racetrack shaped coils that are aligned side by side.

In FIG. 2A, the coil unit 40 is mounted on a top surface 248A of the distribution plate assembly 48. As illustrated in FIG. 2A, one or more sealers 254 (e.g., O-rings) can be positioned between the coil unit 40 and the distribution plate assembly 48 to connect one or more distribution fluid passageways 248B (illustrated in phantom) in the distribution plate assembly 248 to the coil unit 40. With this design, the coil unit 40 can be urged against the distribution plate assembly 48 to seal the distribution fluid passageways 248B in the distribution plate assembly 48 to the desired fluid passageways (not shown) in the coil unit 40.

The distribution plate assembly 48 is generally rectangular shaped and includes the top surface 248A, an opposed bottom surface 248C and a plurality of distribution fluid passageways 248B that connect the fluid distribution network 28 to the coil units 40. Additionally, the distribution plate assembly 48 can include a separate unit aperture 248D (illustrated in phantom) for each coil unit 40. For example, the unit aperture 248D can be a generally rectangular shaped opening that extends between the top surface 248A and the bottom surface 248C that facilitates the attachment of the coil units 40 and electrical connections to the coil units 40. In certain embodiments, a portion of the coil unit 40 extends through the corresponding unit aperture 248D.

Only a very small portion of the fluid distribution network 28 is illustrated in FIG. 2A. Importantly, the fluid distribution network 28 is positioned directly adjacent to the bottom surface 248C of the distribution plate assembly 48. Further, the fluid distribution network 28 is directly attached to the distribution fluid passageways 248B in the distribution plate assembly 48. With this design, the circulation fluid 30 (illustrated in FIG. 1) flows only through the fluid distribution network 28 and a small portion of the distribution plate assembly 48, and not the rest of the countermass assembly 26 (illustrated in FIG. 1).

FIG. 2B is a perspective view of the coil unit 40 including the lower body circulation plate 240A, the coil set 240C, the upper body circulation plate 240D, and the upper surface circulation plate 240F. Additionally, FIG. 2B illustrates that the coil unit 40 includes (i) a body plate inlet 240H that transfers the supply circulation fluid 30 (illustrated in FIG. 1) received from the body fluid source 32 (illustrated in FIG. 1) via the fluid distribution network 28 (illustrated in FIG. 2A) and the distribution plate assembly 48 (illustrated in FIG. 2A) to the body circulation plates 240A, 240D; (ii) a body plate outlet 2401 that transfers the return circulation fluid 30 received from the body circulation plates 240A, 240D to the body fluid source 32 via the distribution plate assembly 48 and the fluid distribution network 28; (iii) a surface plate inlet 240J that transfers the supply circulation fluid 30 received from the surface fluid source 34 via the fluid distribution network 28 and the distribution plate assembly 48 to the surface circulation plate 240F; and (iv) a surface plate outlet 240K that transfers the return circulation fluid 30 received from the surface circulation plate 240F to the surface fluid source 34 via the distribution plate assembly 48 and the fluid distribution network 28.

FIG. 3A is a top plan view of the distribution plate assembly 48 of FIG. 2A. In this embodiment, the distribution plate assembly 48 defines a plurality of coil sites 348A that are each designed to receive, retain, and direct fluid 30 (illustrated in FIG. 1) to one of the coil units 40 (illustrated in FIG. 1). In this embodiment, the distribution plate assembly 48 defines two hundred and sixty-four coil sites 348A. Alternatively, the distribution plate assembly 48 can be designed to have more than or fewer than two hundred and sixty-four coil sites 348A.

As illustrated in FIG. 3A, for each coil site 348A, the distribution plate assembly 48 includes four distribution fluid passageways 248B and a separate unit aperture 248D. In this embodiment, the fluid distribution plate assembly 48 is a modular unit that includes eleven fluid distribution plates 48A that are secured together in a side-by-side manner so as to provide a supporting mechanism to support the plurality of coil units 40.

As noted above, in certain applications, different areas of the stage mover 18 (illustrated in FIG. 1) are used more often than others, thus generating more heat during the movement of the stage 14 (illustrated in FIG. 1). Accordingly, differing amounts of heat can be generated near each of the distribution plate 48A, and, thus, each of the distribution plate 48A can require a differing amount of cooling (which can be controlled in any suitable manner, some of which are noted herein below). For example, in certain applications, the distribution plates 48A can be designated as low use, medium use, or high use, depending on the required usage of the adjacent coil units 40 during movement of the stage 14.

FIG. 3B is a top plan view of one of the distribution plates 48A of FIG. 3A. In this embodiment, each fluid distribution plates 48A is generally rectangular plate shaped and defines twenty-four separate each coil site 348A arranged in two rows of twelve. As provided above, for each coil unit 40, the four distribution fluid passageways 248B can be referred to as (i) a body inlet passageway 348B that is in fluid communication with the body plate inlet 240H (illustrated in FIG. 2B) of the coil unit 40; (ii) a body outlet passageway 348C that is in fluid communication with the body plate outlet 2401 (illustrated in FIG. 2B) of the coil unit 40; (iii) a surface inlet passageway 348D that is in fluid communication with the surface plate inlet 240J (illustrated in FIG. 2B) of the coil unit 40; and (iv) a surface outlet passageway 348E that is in fluid communication with the surface plate outlet 240K (illustrated in FIG. 2B) of the coil unit 40.

In this embodiment, (i) the body inlet passageway 348B and the surface inlet passageway 348D extend completely through the distribution plate 48A, and (ii) the body outlet passageway 348C and the surface outlet passageway 348E extend only partly through the distribution plate 48A.

FIG. 3B also illustrates that each distribution plate 48A includes (i) a body longitudinal passageway 348F (illustrated in phantom) that is in fluid communication with the body outlet passageways 348C; and a spaced apart surface longitudinal passageway 348G (illustrated in phantom) that is in fluid communication with the surface outlet passageways 348E. Further, the longitudinal passageways 348F, 348G extend along the distribution plate 48A. With this design, (i) the fluid 30 (illustrated in FIG. 1) that enters the body outlet passageways 348C is transferred to the body longitudinal passageway 348F, and (ii) the fluid 30 that enters the surface outlet passageways 348E is transferred to the surface longitudinal passageway 348G.

Thus, in certain embodiments, (i) the fluid 30 that has been circulated in each body circulation plate 240A, 240D (illustrated in FIG. 2A) is returned to the common body longitudinal passageway 348F; and (ii) the fluid 30 that has been circulated in each surface circulation plate 240F (illustrated in FIG. 2A) is returned to the common surface longitudinal passageway 348G. This simplifies the pluming for the returning fluid 30. With this design, for each distribution plate 48A, (i) the common body longitudinal passageway 348F functions as a manifold that receives and collects the circulation fluid 30 exiting the body circulation plates 240A, 240D of each coil unit 40; and (ii) the common surface longitudinal passageway 348G functions as a manifold that receives and collects the circulation fluid 30 exiting the surface circulation plate 240F of each coil unit 40.

In certain embodiments, one or more of the passageways 348B, 348C, 348D, 348E can include one or more flow regulators (not illustrated) that regulate the volume and rate of fluid flow to the individual coil units 40. Additionally and/or alternatively, such flow regulators can be included within the structure of the coil units 40 themselves. In one non-exclusive embodiment, one or more of the passageways 348B, 348C, 348D, 348E can be sized and shaped to function as a flow regulator that is sized to provide the desired flow rate based on the planned movement of the mover 18. With this design, the coil units 40 that are used more will be affiliated with flow regulators having larger diameter channels (orifices), and coil units 40 that are used less will be affiliated with flow regulators having smaller diameter channels (orifices). Thus, one or more of the passageways 348B, 348C, 348D, 348E can be sized to suit the flow (cooling) requirements of the respective coil units 40 with the projected usage of the mover 18. Moreover, in one embodiment, the passageways 348B, 348C, 348D, 348E can be sized during the design phase of the mover 18 based on the projected usage of the mover 18 to provide the appropriate flow rate to respective coil units 40.

As a non-exclusive example, four different sizes can be used for the passageways 348B, 348C, 348D, 348E. In this design, (i) the first (largest) diameter can be used for coil units 40 that are used the most; (ii) the second (next largest) diameter can be used for coil units 40 that are used the second most; (iii) the third (largest) diameter can be used for coil units 40 that are used the third most; and (iv) the fourth (largest) diameter can be used for coil units 40 that are used the least. It should be noted that more than four or fewer than four channel diameters can be used.

Alternatively, one or more of the flow regulators can be an adjustable valve that is controlled to adjust and/or regulate the volume and rate of fluid flow depending on the specific cooling requirements for each of the individual coil units 40. In various applications, the control system 22 (illustrated in FIG. 1) can be utilized to provide the necessary and desired regulation of the valves to provide the desired and selective cooling of the individual coil units 40.

As noted above, by providing the relatively short plate passageways 348B, 348C, 348D, 348E, 348F, 348G which are the only fluid paths through the physical structure of the stage assembly 10 (illustrated in FIG. 1), the fluid distribution network 28 (illustrated in FIG. 1) can be more effectively decoupled from the physical structure of the stage assembly 10, so as to more effectively manage the thermal strain that may otherwise exist within the stage assembly 10, e.g., within the stage mover 18 (illustrated in FIG. 1).

FIG. 3C is a bottom plan view of the portion of the distribution plate assembly 48A of FIG. 3B, including the body inlet passageway 348B, the surface inlet passageway 348D, the body longitudinal passageway 348F (illustrated in phantom), and the surface longitudinal passageway 348G (illustrated in phantom).

FIG. 3C also illustrates that, in this non-exclusive embodiment, (i) the body longitudinal passageway 348F includes four outlet passageways 349A that are used to connect the body longitudinal passageway 348F to the body fluid source 32 (illustrated in FIG. 1); and (ii) the surface longitudinal passageway 348G includes two outlet passageways 349B that are used to connect the surface longitudinal passageway 348G to the surface fluid source 34 (illustrated in FIG. 1).

FIG. 3D is a cut-away view of the distribution plate 48A taken on line 3D-3D in FIG. 3C that illustrates the first transverse passageway 348E, the second transverse passageway 348F, one outlet passageways 349A, and one outlet passageway 349B (illustrated in phantom).

In certain embodiments, the distribution plate 48A can be formed from multiple plate members that can be fusion bonded together. In one embodiment, each of the plate members can be formed from a stainless steel material. Alternatively, one or more of the plate members can be formed from another suitable material.

FIG. 4A is a bottom view of the distribution plate 48A, and a portion of the fluid distribution network 28 positioned adjacent to the bottom surface 248C of the distribution plate 48. As provided herein, the majority of the fluid distribution network 28 is positioned below, near and/or substantially adjacent to the bottom surface 248C of the distribution plate assembly 48. With this design, the circulation fluid 30 (illustrated in FIG. 1) does not flow through the bulk of the countermass assembly 26.

In this embodiment, for each distribution plate 48A, the fluid distribution network 28 includes a separate, adjacent conduit assembly 460 that is positioned directly adjacent to the bottom surface 248C of the distribution plate 48A. In one embodiment, the adjacent conduit assembly 460 provides a path below the distribution plate 48A and near and/or substantially adjacent to the bottom surface 248C for directing the circulation fluid 30 (illustrated in FIG. 1) into the distribution plate 48A. For example, the adjacent conduit assembly 460 can include (i) a body supply conduit 462 that is in fluid communication with the body inlet passageway 348B (illustrated in FIG. 3C) of each coil site 348A of the distribution plate 48A; and (ii) a surface supply conduit 464 that is in fluid communication with the surface inlet passageway 348D (illustrated in FIG. 3C) of each coil site 348A of the distribution plate 48A.

With this design, the adjacent conduit assembly 460 is designed to broadly distribute the circulation fluid 30 for the coil sites 348A substantially adjacent to the distribution plate 48A prior to the circulation fluid 30 being directed through the distribution plate 48A in order to provide the desired cooling of the coil units 40 (illustrated in FIG. 1). By effectively distributing the circulation fluid 30 below the distribution plate 48A (i.e. not within the distribution plate assembly 48A), the fluid distribution network 28 can be more effectively decoupled from the physical structure of the countermass assembly 26 (illustrated in FIG. 1), so as to more effectively manage the thermal strain that may otherwise exist.

As provided herein, the adjacent conduit assembly 460 functions as a manifold for the cool inlet circulation fluid 30 into the distribution plate 48A. More specifically, in this embodiment, (i) the body supply conduit 462 is used as a manifold to distribute the inlet circulation fluid 30 of each coil site 348A; and (ii) the surface supply conduit 464 is used as a manifold to distribute the inlet circulation fluid 30 of each coil site 348A. It should be noted that (i) the circulation fluid 30 distributed by the body supply conduit 462 is directed to the body circulation plates 240A, 240D (illustrated in FIG. 2A) of each coil unit 40; and (ii) the circulation fluid 30 distributed by the surface supply conduit 462 is directed to the surface circulation plate 240F (illustrated in FIG. 2A) of each coil unit 40.

It should be noted that the adjacent conduit assembly 460 does not route the heated circulation fluid 30 that has exited each coil unit 40. Thus, because only the adjacent conduit assembly 460 of the fluid distribution network 28 is illustrated in FIG. 4A, (i) the four outlet passageways 349A that are in fluid communication with the body longitudinal passageway 348F (illustrated in FIG. 3C) are still open; and (ii) the two outlet passageways 349B that are in fluid communication with the surface longitudinal passageway 348G (illustrated in FIG. 3C) are still open. Thus, in this embodiment, the adjacent conduit assembly 460 does not route the returning fluid 30 from the coil units 40.

With this design, the adjacent conduit assembly 460 provides a stand alone means for distribution of the circulation fluid 30 (illustrated in FIG. 1) below, near and/or substantially adjacent to the bottom surface 248C of the individual distribution plate 48A. Stated in another fashion, an individual and separate adjacent conduit assembly 460 is utilized to effectively distribute the circulation fluid 30 substantially adjacent to the bottom surface 248C of each distribution plate 48A prior to the circulation fluid 30 being directed through the distribution plate 48A.

FIG. 4B is a bottom view of the adjacent conduit assembly 460 including the body supply conduit 462 and the surface supply conduit 464 from FIG. 4A. In this embodiment, the body supply conduit 462 includes a main body conduit 462A and a plurality of substantially parallel and spaced apart, branch body conduits 462B that cantilever away from and that are in fluid communication with the main body conduit 462A. In this embodiment, each branch body conduit 462B (or the main body conduit 462A near the branch) provides circulation fluid 30 to two coil sites 348A. Thus, the number of branch body conduits 462B is equal to the number of pairs of coil sites 348A for the distribution plate 48A. In FIG. 4B, the body supply conduit 462 includes twelve branch body conduits 462B. Moreover, in this embodiment, the main body conduit 462A includes three spaced apart body conduit inlets 462C to receive the supply circulation fluid 30 (illustrated in FIG. 1) from the body fluid source 32 (illustrated in FIG. 1).

Somewhat similarly, in this embodiment, the surface supply conduit 464 includes a main surface conduit 464A and a plurality of substantially parallel and spaced apart, branch surface conduits 464B that cantilever away from and that are in fluid communication with the main surface conduit 464A. In this embodiment, each branch surface conduit 464B (or the main surface conduit 464A near the branch) provides circulation fluid 30 to two coil sites 348A. Thus, the number of branch surface conduits 464B is equal to the number of pairs of coil sites 348A for the distribution plate 48A. In FIG. 4B, the surface supply conduit 464 includes twelve branch surface conduits 464B. Moreover, in this embodiment, the surface body conduit 464A includes two spaced apart surface conduit inlets 464C to receive the supply circulation fluid 30 (illustrated in FIG. 1) from the body fluid source 34 (illustrated in FIG. 1).

It should be noted that in this embodiment, with reference to FIGS. 4A and 4B, each of the distribution plates 48A includes eleven, separate fluid connection openings, namely four separate body outlet passageways 349A, two separate surface outlet passageways 349B, three body conduit inlets 462C, and two surface conduit inlets 464C (4+2+3+2=11). As a result thereof, the rest of the fluid distribution network 28 must provide fluid connections for the eleven, separate fluid connection openings for each distribution plate 48A.

FIG. 4C is a top view of the adjacent conduit assembly 460 of FIG. 4B. Additionally, FIG. 4D is an enlarged cut-away perspective view of a portion of the adjacent conduit assembly 460 from FIG. 4C. As shown in this embodiment, (i) the body supply conduit 462 include a separate body conduit outlet 462D for each coil site 348A serviced (e.g. twenty four in this example); and (ii) the surface supply conduit 464 include a separate surface conduit outlet 464D for each coil site 348A serviced (e.g. twenty four in this example). For each coil site 348A, (i) the body conduit outlet 462D is in fluid communication with the corresponding body inlet passageway 348B (illustrated in FIG. 3C) of the distribution plate 48A; and (ii) the surface conduit outlet 464D is in fluid communication with the corresponding surface inlet passageway 348D (illustrated in FIG. 3C) of the distribution plate 48A.

It should be noted that (i) half of the branch body conduits 462B include two body conduit outlets 462D, and (ii) half of the branch body conduits 462B include only one body conduit outlet 462D, with the other body conduit outlets 462D being positioned in the main body conduit 462A near the respective branch body conduit 462B. Similarly, (i) half of the branch surface conduits 464B include two surface conduit outlets 464D, and (ii) half of the branch surface conduits 464B include only one surface conduit outlet 464D, with the other surface conduit outlets 464D being positioned in the surface body conduit 464A near the respective branch surface conduit 464B.

It should be understood that in certain embodiments, that the body supply conduit 462 and/or the surface supply conduit 464 can include one or more flow regulators (not illustrated) that individually (or as a group) regulate the volume and rate of the circulation fluid 30 to one or more of the coil sites 348A.

As provided above, the design of the fluid distribution network 28 can be varied to suit the specific requirements of the stage assembly 10 (illustrated in FIG. 1) with which the fluid distribution network 28 is utilized. FIG. 5A is a perspective view of another portion of the fluid distribution network 28. In one embodiment, the portion of the fluid distribution network 28 illustrated in FIG. 5A is used to connect in fluid communication the (i) the body fluid source 32 (illustrated in FIG. 1) to the body supply conduit 462 (illustrated in FIG. 4A) for each distribution plate 48A to supply the body circulation fluid 30 (illustrated in FIG. 1) to each coil unit 40 (illustrated in FIG. 1); (ii) the outlet passageways 349A (illustrated in FIG. 3C) for each distribution plate 48A to the body fluid source 32 to return the body circulation fluid 30 from each coil unit 40; (iii) the surface fluid source 34 (illustrated in FIG. 1) to the surface supply conduit 464 (illustrated in FIG. 4A) for each distribution plate 48A to supply the surface circulation fluid 30 (illustrated in FIG. 1) to each coil unit 40 (illustrated in FIG. 1); and (iv) the outlet passageways 349B (illustrated in FIG. 3C) for each distribution plate 48A to the surface fluid source 34 to return the surface circulation fluid 30 from each coil unit 40.

In one embodiment, the portion of the fluid distribution network 28 illustrated in FIG. 5A is positioned below and adjacent to the body supply conduit 462 and the surface supply conduit 464 for each distribution plate 48A. With this design, the fluid distribution network 28 is substantially thermally decoupled from the rest of the countermass assembly 26.

In the non-exclusive embodiment illustrated in FIG. 5A, the fluid distribution network 28 includes (i) a first distribution hub 570 (also sometimes referred to as a “first gorgon”), (ii) a second distribution hub 572 (also sometimes referred to as a “second gorgon”) that is a spaced apart from and that is a mirror image of the first distribution hub 570; and (iii) a distribution conduit array 574 (also sometimes referred to as “qanats”) that is in fluid communication with the distribution hubs 570, 572. In this embodiment, (i) the distribution hubs 570, 572 are connected to and are in fluid communication with the fluid sources 34, 36; and (ii) the distribution conduit array 574 is in fluid communication with the eleven, separate fluid connection openings, namely four separate body outlet passageways 349A, two separate surface outlet passageways 349B, three body conduit inlets 462C, and two surface conduit inlets 464C (see FIGS. 4A and 4B) for each distribution plate 48A. As provided above, in the embodiment illustrated in FIG. 3A, the distribution plate assembly 48 includes eleven separate distribution plates 48A. Further, each distribution plate 48A includes eleven separate fluid connection openings. Thus, in this embodiment, the distribution conduit array 574 is designed provide a separate fluid connection 576 to the one hundred and twenty-one different fluid connection openings of the distribution plate assembly 48. In FIG. 5A, the distribution conduit array 574 includes eleven separate, substantially equally spaced apart and substantially parallel, distribution conduits 578 and each distribution conduit 578 includes eleven separate fluid connections 576 to provide fluid connections to the one hundred and twenty-one different fluid connection openings of the distribution plate assembly 48.

Each of the eleven separate fluid connections 576 of each of the distribution conduits 578 is connected in fluid communication to a different one of the distribution plates 48A. Stated in another fashion, for each distribution plate 48A, each distribution conduits 578 provides a single separate fluid connection 576. Thus, in this design, the distribution conduits 578 are positioned transverse to the long axis of each distribution plate 48A. As a result thereof, each of the distribution conduits 578 extends over each of the distribution plates 48A.

It should be noted that with the present design, the fluid distribution network 28 can easily be scaled to fit a distribution plate assembly 48 that is sized differently than provided herein.

FIG. 5B is a top view of the first distribution hub 570, the second distribution hub 572 and the distribution conduit array 574. Additionally, one of the eleven side-by-side distribution plates 48A and its corresponding adjacent conduit assembly 460 is illustrated in phantom for reference. As provided above, each distribution conduit 578 is in fluid communication once via the eleven separate fluid connections 576 to each distribution plate 48A.

In this embodiment, as provided above, the distribution conduit array 574 includes eleven distribution conduits 578 that are substantially parallel to one another, and each of the distribution conduits 578 extends along (or parallel to) a first axis, e.g., the Y axis (transverse to the distribution plates 48A); and the distribution conduits 578 are spaced apart from one another along (or parallel to) a second axis, e.g., the X axis. Alternatively, the fluid distribution network 28 can be designed to include greater than eleven or less than eleven distribution conduits 578, and/or the distribution conduits 578 can have a different positioning and/or orientation relative to one another.

As provided herein, the fluid distribution network 28 is in fluid communication with the fluid sources 34, 36 to provide the necessary and desired fluid path for (i) the inlet body circulation fluid 30 (illustrated in FIG. 1) from the body fluid source 32 that is to be delivered to body circulation plates 240A, 240D of each coil unit 40; (ii) the returning body circulation fluid 30 from the body circulation plates 240A, 240D of each coil unit 40 to the body fluid source 32; (iii) the inlet surface circulation fluid 30 from the surface fluid source 34 that is to be delivered to surface circulation plate 240F of each coil unit 40; and (iv) the returning surface circulation fluid 30 from the surface circulation plate 240F of each coil unit 40 to the surface fluid source 34.

In FIG. 5B, the first distribution hub 570 and the second distribution hub 572 cooperate to be in fluid communication twice with each distribution conduit 578. Further, in the non-exclusive embodiment illustrated in FIG. 5B, the fluid distribution network 28 is designed and plumed so that (i) three of the distribution conduits 578 (labeled 578B1) carry inlet body circulation fluid 30 from the body fluid source 32; (ii) four of the distribution conduits 578 (labeled 578BR) carry returning body circulation fluid 30 from the distribution plates 48A; (iii) two of the distribution conduits 578 (labeled 578S1) carry inlet surface circulation fluid 30 from the surface fluid source 34; and (iv) two of the distribution conduits 578 (labeled 578SR) carry returning surface circulation fluid 30 from the distribution plates 48A. With this embodiment, the eleven distribution conduits 578 can each be coupled once for each of the distribution plates 48A at the eleven, separate fluid connection openings, namely four separate body outlet passageways 349A, two separate surface outlet passageways 349B, three body conduit inlets 462C, and two surface conduit inlets 464C (see FIGS. 4A and 4B).

The arrangement of the distribution conduits 578 can vary. In the non-exclusive embodiment illustrated in FIG. 5B, moving from the top to bottom, the distribution conduits 578 are arranged as follows: (i) the first distribution conduit 578 is labeled 578BR because it is carrying returning body circulation fluid 30; (ii) the second distribution conduit 578 is labeled 578SS because it is carrying inlet (supply) surface circulation fluid 30; (iii) the third distribution conduit 578 is labeled 578SR because it is carrying returning surface circulation fluid 30; (iv) the fourth distribution conduits 578 is labeled 578BS because it is carrying inlet (supply) body circulation fluid 30; (v) the fifth distribution conduit 578 is labeled 578BR because it is carrying returning body circulation fluid 30; (vi) the sixth distribution conduit 578 is labeled 578BS because it is carrying inlet (supply) body circulation fluid 30; (vii) the seventh distribution conduit 578 is labeled 578BR because it is carrying returning body circulation fluid 30; (viii) the eighth distribution conduit 578 is labeled 578BS because it is carrying inlet (supply) body circulation fluid 30; (ix) the ninth distribution conduit 578 is labeled 578SR because it is carrying returning surface circulation fluid 30; (x) tenth distribution conduit 578 is labeled 578SS because it is carrying inlet (supply) surface circulation fluid 30; and (xi) the eleventh distribution conduit 578 is labeled 578BR because it is carrying returning body circulation fluid 30;

Further, the first distribution hub 570 is connected (i) twice to the first distribution conduit 578, the second distribution conduit 578, the third distribution conduit 578, the fourth distribution conduits 578, and the fifth distribution conduit 578; and (i) once to the sixth distribution conduit 578.

Somewhat similarly, the second distribution hub 572 is connected (i) once to the sixth distribution conduit 578 and (i) twice to the seventh distribution conduit 578, the eighth distribution conduit 578, the ninth distribution conduit 578, the tenth distribution conduits 578, and the eleventh distribution conduit 578.

It should be noted that fluid distribution network 28 can include one or more valves or regulars (not shown) that can be used to regulate flow.

FIG. 6A is a bottom perspective view, FIG. 6B is a top view, and is an inverted side view of the distribution conduit array 574. As provided above each distribution conduit 578 includes eleven, spaced apart, separate fluid connections 576, with one fluid connector from each distribution conduit 578 being connected each distribution plate 48A or corresponding adjacent conduit assembly 460. Additionally, in this embodiment, each distribution conduit 578 includes one or more hub connectors 680 for fluid connection to the respective distribution hub 570, 572. In the specific illustrated embodiment, each distribution conduit 578 includes two space apart hub connectors 680, which can function as either an inlet to or an outlet from the respective distribution conduit 578 depending on whether the individual distribution conduit 578 is part of the fluid supply trip or the fluid return trip.

FIG. 6C illustrates the size and positioning of the hub connectors 680 and the fluid connections 576 along the length of one of the distribution conduits 578.

FIG. 7A is a bottom perspective view, and FIG. 7B is a bottom view of the distribution hubs 570, 572 of the fluid distribution network 28. In this embodiment, the first distribution hub 570 includes (i) a first manifold 782 having a plurality of manifold openings 784 that are connected to and that are in fluid communication with the fluid sources 34, 36, and (ii) eleven, first manifold conduits 786 that are in fluid communication with the first manifold 782. Similarly, the second distribution hub 572 includes (i) a second manifold 788 having a plurality of manifold openings 790 that are connected to and that are in fluid communication with the fluid sources 34, 36, and (ii) eleven, second manifold conduits 792 that are in fluid communication with the second manifold 786.

The number of manifold openings 784, 790, and manifold conduits 786, 792 can be varied to suit the requirements of the system. In one embodiment, the first distribution hub 570 include eleven manifold openings 784, and eleven manifold conduits 786; and the second distribution hub 572 include eleven manifold openings 790, and eleven manifold conduits 792.

The fluid distribution network 28 is designed and plumed so that (i) three of the first manifold openings 784 and three of the first manifold conduits 786 carry inlet body circulation fluid 30 from the body fluid source 32; (ii) four of the first manifold openings 784 and four of the first manifold conduits 786 carry returning body circulation fluid 30 from the distribution plates 48A; (iii) two of the first manifold openings 784 and two of the first manifold conduits 786 carry inlet surface circulation fluid 30 from the surface fluid source 34; (iv) two of the first manifold openings 784 and two of the first manifold conduits 786 carry returning surface circulation fluid 30 from the distribution plates 48A; (v) three of the second manifold openings 790 and three of the second manifold conduits 792 carry inlet body circulation fluid 30 from the body fluid source 32; (vi) four of the second manifold openings 790 and four of the second manifold conduits 792 carry returning body circulation fluid 30 from the distribution plates 48A; (vii) two of the second manifold openings 790 and two of the second manifold conduits 792 carry inlet surface circulation fluid 30 from the surface fluid source 34; and (viii) two of the second manifold openings 790 and two of the second manifold conduits 792 carry returning surface circulation fluid 30 from the distribution plates 48A

FIG. 8A is a perspective view of a connector 894 that can be used to connect a portion of the fluid distribution network 28 (illustrated in FIG. 1) to the distribution plate 48A (illustrated in FIG. 1). Additionally, FIG. 8B is a perspective view of a portion of the distribution plate 48A and the connector 894. In one embodiment, the connector 894 can be a hollow bolt that extends into and partially through a plate aperture 848A to provide the desired feed-through for connection of the fluid conduits.

As illustrated the connector 894 can be annular-shaped, with a substantially circular cross-section, and having an upper section 894A and a lower section 894B that is slightly smaller in outer circumference than the upper section 894A. Additionally, the plate aperture 848A can also have a substantially circular cross-section, and have an upper portion 848B through which the entire connector 894 can fit, and a lower portion 848C through which only the lower section 894B of the connector 894 can fit. With this design, the connector 894 can effectively sit on a ledge within the plate aperture 848A in order to provide the desired feed-through connection with the conduits.

In certain embodiments, the orifice of the connector 894 can be sized to regulate the volume and rate of fluid flow between the distribution plates 48A. In this embodiment, the larger diameter orifices can be used for distribution plates 48A that are used more and that require more cooling, while smaller diameter orifices are used for distribution plates 48A that are used less and that require less cooling. Thus, the orifices can be sized to suit the flow (cooling) requirements of the respective distribution plate 48A. Moreover, the orifices can be sized during the design phase of the mover 18 based on the projected usage of the mover 18 to provide the appropriate flow rate to respective distribution plates 48A.

FIG. 9 is a schematic illustration of a precision assembly, namely an exposure apparatus 934 useful with the present invention. The exposure apparatus 934 includes an apparatus frame 987, an illumination system 988 (irradiation apparatus), an optical assembly 989 (lens assembly), a reticle stage assembly 990, a wafer stage assembly 991, a measurement system 992, and a control system 993. The design of the various components of the exposure apparatus 934 can be varied to suit the specific requirements of the exposure apparatus 934. In certain applications, the various stage assemblies, as described in detail herein, can be used as the wafer stage assembly 991. Alternatively, with the disclosure provided herein, the stage assemblies provided herein can be modified for use as the reticle stage assembly 990.

The exposure apparatus 934 is particularly useful as a lithographic device that transfers a pattern (not shown) of an integrated circuit from a reticle 994 onto a semiconductor wafer 995. The exposure apparatus 934 mounts to a mounting base 924, e.g., the ground, a base, or floor or some other supporting structure.

There are a number of different types of lithographic devices. For example, the exposure apparatus 934 can be used as a scanning type photolithography system that exposes the pattern from the reticle 994 onto the wafer 995 with the reticle 994 and the wafer 995 moving synchronously. Alternatively, the exposure apparatus 934 can be a step-and-repeat type photolithography system that exposes the reticle 994 while the reticle 994 and the wafer 995 are stationary.

However, the use of the exposure apparatus 934 and stage assemblies provided herein is not limited to a photolithography system for semiconductor manufacturing. The exposure apparatus 934, for example, can be used as an LCD photolithography system that exposes a liquid crystal display device pattern onto a rectangular glass plate or a photolithography system for manufacturing a thin film magnetic head. Further, the present invention can also be applied to a proximity photolithography system that exposes a mask pattern by closely locating a mask and a substrate without the use of a lens assembly. Additionally, the present invention provided herein can be used in other devices, including other semiconductor processing equipment, elevators, machine tools, metal cutting machines, inspection machines and disk drives.

The apparatus frame 987 is rigid and supports the components of the exposure apparatus 934. The design of the apparatus frame 987 can be varied to suit the design requirements of the rest of the exposure apparatus 934. The apparatus frame 987 illustrated in FIG. 9 supports the optical assembly 989, the reticle stage assembly 990, the wafer stage assembly 991, and the illumination system 988 above the mounting base 924.

The illumination system 988 includes an illumination source 996 and an illumination optical assembly 997. The illumination source 996 emits a beam (irradiation) of light energy. The illumination optical assembly 997 guides the beam of light energy from the illumination source 996 to the optical assembly 989. The beam of light energy selectively illuminates different portions of the reticle 994 and exposes the wafer 995. In FIG. 9, the illumination source 996 is illustrated as being supported above the reticle stage assembly 990. Alternatively, the illumination source 996 can be secured to one of the sides of the apparatus frame 987 and the energy beam from the illumination source 996 can be directed to above the reticle stage assembly 990 with the illumination optical assembly 997.

The illumination source 996 can be a g-line source (436 nm), an i-line source (365 nm), a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), a F₂ laser (157 nm), or an EUV source (13.5 nm). Alternatively, the illumination source 996 can generate charged particle beams such as an x-ray or an electron beam. For instance, in the case where an electron beam is used, thermionic emission type lanthanum hexaboride (LaB₆) or tantalum (Ta) can be used as a cathode for an electron gun. Furthermore, in the case where an electron beam is used, the structure could be such that either a mask is used or a pattern can be directly formed on a substrate without the use of a mask.

The optical assembly 989 projects and/or focuses the light passing through the reticle 994 to the wafer 995. Depending upon the design of the exposure apparatus 934, the optical assembly 989 can magnify or reduce the image illuminated on the reticle 994. The optical assembly 989 need not be limited to a reduction system. It could also be a 1× or magnification system.

The reticle stage assembly 990 holds and positions the reticle 994 relative to the optical assembly 989 and the wafer 995. Similarly, the wafer stage assembly 991 holds and positions the wafer 995 with respect to the projected image of the illuminated portions of the reticle 994.

The measurement system 992 monitors movement of the reticle 994 and the wafer 995 relative to the optical assembly 989 or some other reference. With this information, the control system 993 can control the reticle stage assembly 990 to precisely position the reticle 994 and the wafer stage assembly 991 to precisely position the wafer 995. For example, the measurement system 992 can utilize multiple laser interferometers, encoders, autofocus systems, and/or other measuring devices.

The control system 993 is connected to the reticle stage assembly 990, the wafer stage assembly 990, and the measurement system 992. The control system 993 receives information from the measurement system 992 and controls the stage assemblies 990, 991 to precisely position the reticle 994 and the wafer 995. The control system 993 can include one or more processors and circuits.

As described above, a photolithography system according to the above described embodiments can be built by assembling various subsystems, including each element listed in the appended claims, in such a manner that prescribed mechanical accuracy, electrical accuracy, and optical accuracy are maintained. In order to maintain the various accuracies, prior to and following assembly, every optical system is adjusted to achieve its optical accuracy. Similarly, every mechanical system and every electrical system are adjusted to achieve their respective mechanical and electrical accuracies. The process of assembling each subsystem into a photolithography system includes mechanical interfaces, electrical circuit wiring connections and air pressure plumbing connections between each subsystem. Needless to say, there is also a process where each subsystem is assembled prior to assembling a photolithography system from the various subsystems. Once a photolithography system is assembled using the various subsystems, a total adjustment is performed to make sure that accuracy is maintained in the complete photolithography system. Additionally, it is desirable to manufacture an exposure system in a clean room where the temperature and cleanliness are controlled.

Semiconductor devices can be fabricated using the above described systems, by the process shown generally in FIG. 10A. In step 1001 the device's function and performance characteristics are designed. Next, in step 1002, a mask (reticle) having a pattern is designed according to the previous designing step, and in a parallel step 1003 a wafer is made from a silicon material. The mask pattern designed in step 1002 is exposed onto the wafer from step 1003 in step 1004 by a photolithography system described hereinabove in accordance with the present invention. In step 1005 the semiconductor device is assembled (including the dicing process, bonding process and packaging process), finally, the device is then inspected in step 1006.

FIG. 10B illustrates a detailed flowchart example of the above-mentioned step 1004 in the case of fabricating semiconductor devices. In FIG. 10B, in step 1011 (oxidation step), the wafer surface is oxidized. In step 1012 (CVD step), an insulation film is formed on the wafer surface. In step 1013 (electrode formation step), electrodes are formed on the wafer by vapor deposition. In step 1014 (ion implantation step), ions are implanted in the wafer. The above mentioned steps 1011-1014 form the preprocessing steps for wafers during wafer processing, and selection is made at each step according to processing requirements.

At each stage of wafer processing, when the above-mentioned preprocessing steps have been completed, the following post-processing steps are implemented. During post-processing, first, in step 1015 (photoresist formation step), photoresist is applied to a wafer. Next, in step 1016 (exposure step), the above-mentioned exposure device is used to transfer the circuit pattern of a mask (reticle) to a wafer. Then in step 1017 (developing step), the exposed wafer is developed, and in step 1018 (etching step), parts other than residual photoresist (exposed material surface) are removed by etching. In step 1019 (photoresist removal step), unnecessary photoresist remaining after etching is removed.

Multiple circuit patterns are formed by repetition of these preprocessing and post-processing steps.

While a number of exemplary aspects and embodiments of a stage assembly 10 and a fluid distribution network 28 have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope. 

What is claimed is:
 1. A reaction assembly for supporting a mover relative to a base, the reaction assembly comprising: a countermass assembly that supports a portion of the mover; and a fluid distribution network that provides cooling for the portion of the mover, the fluid distribution network being positioned substantially adjacent to the countermass assembly, the fluid distribution network being substantially decoupled from the structure of the countermass assembly to inhibit thermal deformation of the countermass assembly.
 2. The reaction assembly of claim 1 wherein the countermass assembly includes a distribution plate assembly, and wherein a majority of the fluid distribution network is positioned below and substantially adjacent to a bottom surface of the distribution plate assembly.
 3. The reaction assembly of claim 2 wherein the distribution plate assembly includes a plurality of unit apertures, each coil unit is positioned near one of the unit apertures.
 4. The reaction assembly of claim 3 wherein the fluid distribution network includes a Coil Temperature Control network for cooling individual coils within the coil units, and a Surface Temperature Control network for cooling a surface of the coil units.
 5. The reaction assembly of claim 3 wherein the distribution plate assembly includes a plurality of passageways that extend between the fluid distribution network and the coil units, the passageways providing the only source of circulation fluid within the distribution plate assembly.
 6. A stage assembly including a stage base, a stage that retains a device, a stage mover that moves the stage relative to the stage base, and the reaction assembly of claim 1 that supports a portion of the stage mover.
 7. The stage assembly of claim 6 wherein the portion of the stage mover includes a conductor array having a plurality of coil units, and wherein the fluid distribution network provides cooling for the coil units.
 8. A reaction assembly for supporting a mover relative to a base, the reaction assembly comprising: a countermass assembly that supports a portion of the mover, the countermass assembly including a distribution plate assembly; and a fluid distribution network that cools the portion of the mover, a majority of the fluid distribution network being positioned below and substantially adjacent to a bottom surface of the distribution plate assembly.
 9. The reaction assembly of claim 8 wherein the fluid distribution network is substantially decoupled from the structure of the countermass assembly to inhibit thermal deformation of the countermass assembly.
 10. The reaction assembly of claim 8 wherein the distribution plate assembly includes a plurality of unit apertures, one of a plurality of coil units is positioned near each unit aperture.
 11. The reaction assembly of claim 8 wherein the fluid distribution network is adapted to supply circulation fluid to the coil units to cool the coil units.
 12. The reaction assembly of claim 8 wherein the fluid distribution network includes a Coil Temperature Control network for cooling individual coils within the coil units, and a Surface Temperature Control network for cooling a surface of the coil units.
 13. The reaction assembly of claim 8 wherein the distribution plate assembly includes a plurality of passageways that extend between the fluid distribution network and the coil units, the passageways providing the only source of circulation fluid within the distribution plate assembly.
 14. A stage assembly including a stage base, a stage that retains a device, a stage mover that moves the stage relative to the stage base, and the reaction assembly of claim 8 that supports a portion of the stage mover.
 15. The stage assembly of claim 14 wherein the portion of the stage mover includes a conductor array having a plurality of coil units, and wherein the fluid distribution network provides cooling for the coil units.
 16. A reaction assembly for supporting a mover relative to a base, the reaction assembly comprising: a distribution plate assembly that supports a portion of the mover, the distribution plate assembly including a plurality of plate passageways; and a fluid distribution network including a fluid source that provides a circulation fluid that cools the portion of the mover, wherein the plate passageways extend between the fluid distribution network and the portion of the mover, the plate passageways providing the only source of the circulation fluid within the distribution plate assembly.
 17. The reaction assembly of claim 16 wherein a majority of the fluid distribution network is positioned below and substantially adjacent to a bottom surface of the distribution plate assembly.
 18. The reaction assembly of claim 16 wherein the fluid distribution network is substantially decoupled from the structure of the distribution plate assembly to inhibit thermal deformation of the distribution plate assembly.
 19. The reaction assembly of claim 16 wherein the distribution plate assembly includes a plurality of unit apertures, one of a plurality of coil units is positioned near each unit aperture.
 20. The reaction assembly of claim 16 wherein the fluid distribution network includes a Coil Temperature Control network for cooling individual coils within the coil units, and a Surface Temperature Control network for cooling a surface of the coil units. 